16 BIRDS OF CALIFORNIA AFFECTING FRUIT INDUSTRY. 
Of the contents of the 27 stomachs, 78 percent consisted of animal 
matter, nearly all of which was either insects or spiders. The remain- 
ing 22 percent was made up of various vegetable substances. In the 
relative proportions of animal and vegetable food the California bird 
differs somewhat from the eastern subspecies, the diet of which con- 
sists of 68 percent of animal matter to 32 of vegetable. 
Animal food.—Of the various items in the food of the western 
hairy woodpecker, the most important, as well as the largest, is the 
larvee of wood-boring beetles (Cerambycide and Buprestide). These 
aggregate for the year nearly 49 percent of the total. This is a much 
greater proportion than is eaten by the eastern subspecies, and is 
probably not exceeded by any other bird. Each of several stomachs 
contained more than 20 larve. When the immense damage done by 
these borers to forest trees, as well as to orchards, is considered, it is 
hardly possible to overestimate the value of this woodpecker’s serv- 
ices. Moreover, these insects are concealed and protected from the 
attacks of all birds except those of this family. Most of these insects 
are taken in the cooler months, the fewest being eaten in July. One 
stomach taken in February contained 70 percent of wood-borers, and 
the remainder, or 30 percent, consisted of other harmful beetles. 
Two stomachs taken in April contained an average of 76 percent of 
these destructive borers and 6 percent of other beetles. Beetles 
belonging to various families, nearly all of them harmful, and some 
very injurious, amount to over 9 percent of the food. 
Ants are usually a favorite article of food with woodpeckers, but 
with the California hairy woodpeckers they constitute less than 3 
percent of the year’s food. This is somewhat surprising, as the 
eastern bird eats them to the extent of 17 percent. Other Hymenop- 
tera, including wasps, amount to less than 2 percent. 
Caterpillars exceed 11 percent, and stand next to beetles in im- 
portance. Many.of them are of wood-boring species and evidently 
were dug out of trees. 
A few miscellaneous insects and some spiders complete the animal 
food. Several stomachs contained segments of millepeds, or thou- 
sand legs, and one held the remains of one of those bristly creatures 
known as jointed spiders (Solpugide). 
Vegetable food.—The vegetable part of the diet may be divided into 
fruit, seeds, and miscellaneous substances. Fruit amounts to 6 per- 
cent, and consists ef the smaller kinds, probably mostly wild species. 
Rubus seeds (raspberry or blackberry), found in several stomachs, 
were the only fruits positively identified. Seeds aggregate nearly 12 
percent, and all that were determined belonged to coniferous trees. 
The miscellaneous part contains a little mast and some cambium, 
or inner bark, but is mostly rubbish, such as rotten wood, probably 
swallowed accidentally with the beetle larve. 
